Cardiovascular disease (CVD) is the number one killer and a major cause of disability in the United States. Emerging data suggest that overproduction of reactive oxygen species (ROS) plays a causal role in the pathogenesis of atherosclerosis and other CVD. Reactive nitrogen intermediates such as peroxynitrite (ONOO-) and nitrogen-dioxide radicals, formed by rapid reaction between nitric oxide (.NO) and ROS, react with carbohydrates, DNA bases, protein tyrosine/tryptophan, and unsaturated fatty acids to form relatively stable nitrated products. In the past eight years, our research team has revealed that a novel class of nitrated unsaturated fatty acids (NO2-FA) is generated by NO- mediated oxidative reactions and exerts pleiotropic cell signaling actions with a property of anti-oxidative stress. Recently, we have well documented that NO2- FA exerted anti-proliferative and pro-apoptotic effects in vascular smooth muscle cells (VSMC) via activation of Nrf2 with an increase in Nrf2 stability in vitro. Furthermore, we have demonstrated that NO2-FA inhibited vascular lesion formation after arterial injury. These key results let us to test our central hypothesis that NO2-FA-operated Nrf2 signaling play a critical role in protecting vasculature from vascular lesion formation, thereby contributing to maintenance of vascular homeostasis. As Nrf2 signaling is critical for the anti-oxidative defense in various organs including the cardiovascular system, understanding of the endogenous NO2-FA-operated Nrf2 signaling will provide novel insights into redox homeostasis and the development of new therapeutic strategies for the treatment of CVD. Specifically, we will 1) Define NO2-FA-operated Nrf2 signaling in the control of VSMC fate in vitro;2) Define the mechanisms of NO2-FA- mediated Nrf2 activation in VSMC;3) Determine the NO2-FA-operated Nrf2 signaling as a "vasculo-protective" determinant in vascular lesion formation in vivo. PUBLIC HEALTH RELEVANCE: Cardiovascular disease (CVD) is the number one killer and a major cause of disability in the United States. Overproduction of reactive oxygen species (ROS) plays a causal role in the pathogenesis of CVD;however, nonselective approach of scavenging all ROS appears to have deleterious effects. This proposal will address the "vasculo-protective" effect of nitro-fatty acids (NO2-FA), which is mediated by activation of Nrf2 signaling, an anti-oxidative system. The outcome of these studies will provide novel perspectives for the rational design and development of NO2-FA derivatives with unique properties of enhancing of anti-oxidative defense rather than simply blockade of ROS production for CVD treatment.